1. Field of the Invention
This invention relates to a liquid crystal device constituting a liquid crystal display (LCD), a liquid crystal light valve (LCLV) for use in a liquid crystal printer, or other kinds of apparatuses.
2. Description of the Related Art
An ordinary liquid crystal device has a structure in which a liquid crystal material is interposed between two substrates and peripheral portions of the substrates are sealed with a sealing material.
Conventionally, the same types of material are used as such two substrates. But, if a silicon wafer is used as a TFT substrate as in the case of an active matrix LCD, the same Si wafer cannot be used as the other of the two substrates. In this case, a transparent substrate is used instead of the Si wafer substrate, because the Si wafer is not light-transmissive. Also, if a quartz glass member is used as a TFT substrate instead of Si wafer, a low-priced transparent substrate is used as the other of the two substrates by considering the production cost.
However, a problem arises since glass #7059, a product from Corning Inc., generally used as low-alkali glass, has a thermal expansion coefficient greatly different from that of the Si wafer. If two substrates formed of such glass and a silicon wafer are bonded to each other and set by heat, a thermal strain remains and a problem of a warp of cells arises. In such a case, it is difficult to manufacture a desired liquid crystal device. This has been one of the causes of difficulty in improving the yield.
On the other hand, to optimize the desired high-performance of a liquid crystal device, it is necessary to selectively use substrates formed of different materials including those differing in composition and crystalline structure, according to one's need.